# (c) 2005 Ian Bicking and contributors; written for Paste (http://pythonpaste.org)
# Licensed under the MIT license: http://www.opensource.org/licenses/mit-license.php
"""
Map URL prefixes to WSGI applications. See ``URLMap``
"""
from UserDict import DictMixin
import re
import os
import cgi
from paste import httpexceptions
__all__ = ['URLMap', 'PathProxyURLMap']
def urlmap_factory(loader, global_conf, **local_conf):
if 'not_found_app' in local_conf:
not_found_app = local_conf.pop('not_found_app')
else:
not_found_app = global_conf.get('not_found_app')
if not_found_app:
not_found_app = loader.get_app(not_found_app, global_conf=global_conf)
urlmap = URLMap(not_found_app=not_found_app)
for path, app_name in local_conf.items():
path = parse_path_expression(path)
app = loader.get_app(app_name, global_conf=global_conf)
urlmap[path] = app
return urlmap
def parse_path_expression(path):
"""
Parses a path expression like 'domain foobar.com port 20 /' or
just '/foobar' for a path alone. Returns as an address that
URLMap likes.
"""
parts = path.split()
domain = port = path = None
while parts:
if parts[0] == 'domain':
parts.pop(0)
if not parts:
raise ValueError("'domain' must be followed with a domain name")
if domain:
raise ValueError("'domain' given twice")
domain = parts.pop(0)
elif parts[0] == 'port':
parts.pop(0)
if not parts:
raise ValueError("'port' must be followed with a port number")
if port:
raise ValueError("'port' given twice")
port = parts.pop(0)
else:
if path:
raise ValueError("more than one path given (have %r, got %r)"
% (path, parts[0]))
path = parts.pop(0)
s = ''
if domain:
s = 'http://%s' % domain
if port:
if not domain:
raise ValueError("If you give a port, you must also give a domain")
s += ':' + port
if path:
if s:
s += '/'
s += path
return s
class URLMap(DictMixin):
"""
URLMap instances are dictionary-like object that dispatch to one
of several applications based on the URL.
The dictionary keys are URLs to match (like
``PATH_INFO.startswith(url)``), and the values are applications to
dispatch to. URLs are matched most-specific-first, i.e., longest
URL first. The ``SCRIPT_NAME`` and ``PATH_INFO`` environmental
variables are adjusted to indicate the new context.
URLs can also include domains, like ``http://blah.com/foo``, or as
tuples ``('blah.com', '/foo')``. This will match domain names; without
the ``http://domain`` or with a domain of ``None`` any domain will be
matched (so long as no other explicit domain matches). """
def __init__(self, not_found_app=None):
self.applications = []
if not not_found_app:
not_found_app = self.not_found_app
self.not_found_application = not_found_app
norm_url_re = re.compile('//+')
domain_url_re = re.compile('^(http|https)://')
def not_found_app(self, environ, start_response):
mapper = environ.get('paste.urlmap_object')
if mapper:
matches = [p for p, a in mapper.applications]
extra = 'defined apps: %s' % (
',\n '.join(map(repr, matches)))
else:
extra = ''
extra += '\nSCRIPT_NAME: %r' % environ.get('SCRIPT_NAME')
extra += '\nPATH_INFO: %r' % environ.get('PATH_INFO')
extra += '\nHTTP_HOST: %r' % environ.get('HTTP_HOST')
app = httpexceptions.HTTPNotFound(
environ['PATH_INFO'],
comment=cgi.escape(extra)).wsgi_application
return app(environ, start_response)
def normalize_url(self, url, trim=True):
if isinstance(url, (list, tuple)):
domain = url[0]
url = self.normalize_url(url[1])[1]
return domain, url
assert (not url or url.startswith('/')
or self.domain_url_re.search(url)), (
"URL fragments must start with / or http:// (you gave %r)" % url)
match = self.domain_url_re.search(url)
if match:
url = url[match.end():]
if '/' in url:
domain, url = url.split('/', 1)
url = '/' + url
else:
domain, url = url, ''
else:
domain = None
url = self.norm_url_re.sub('/', url)
if trim:
url = url.rstrip('/')
return domain, url
def sort_apps(self):
"""
Make sure applications are sorted with longest URLs first
"""
def key(app_desc):
(domain, url), app = app_desc
if not domain:
# Make sure empty domains sort last:
return '\xff', -len(url)
else:
return domain, -len(url)
apps = [(key(desc), desc) for desc in self.applications]
apps.sort()
self.applications = [desc for (sortable, desc) in apps]
def __setitem__(self, url, app):
if app is None:
try:
del self[url]
except KeyError:
pass
return
dom_url = self.normalize_url(url)
if dom_url in self:
del self[dom_url]
self.applications.append((dom_url, app))
self.sort_apps()
def __getitem__(self, url):
dom_url = self.normalize_url(url)
for app_url, app in self.applications:
if app_url == dom_url:
return app
raise KeyError(
"No application with the url %r (domain: %r; existing: %s)"
% (url[1], url[0] or '*', self.applications))
def __delitem__(self, url):
url = self.normalize_url(url)
for app_url, app in self.applications:
if app_url == url:
self.applications.remove((app_url, app))
break
else:
raise KeyError(
"No application with the url %r" % (url,))
def keys(self):
return [app_url for app_url, app in self.applications]
def __call__(self, environ, start_response):
host = environ.get('HTTP_HOST', environ.get('SERVER_NAME')).lower()
if ':' in host:
host, port = host.split(':', 1)
else:
if environ['wsgi.url_scheme'] == 'http':
port = '80'
else:
port = '443'
path_info = environ.get('PATH_INFO')
path_info = self.normalize_url(path_info, False)[1]
for (domain, app_url), app in self.applications:
if domain and domain != host and domain != host+':'+port:
continue
if (path_info == app_url
or path_info.startswith(app_url + '/')):
environ['SCRIPT_NAME'] += app_url
environ['PATH_INFO'] = path_info[len(app_url):]
return app(environ, start_response)
environ['paste.urlmap_object'] = self
return self.not_found_application(environ, start_response)
class PathProxyURLMap(object):
"""
This is a wrapper for URLMap that catches any strings that
are passed in as applications; these strings are treated as
filenames (relative to `base_path`) and are passed to the
callable `builder`, which will return an application.
This is intended for cases when configuration files can be
treated as applications.
`base_paste_url` is the URL under which all applications added through
this wrapper must go. Use ``""`` if you want this to not
change incoming URLs.
"""
def __init__(self, map, base_paste_url, base_path, builder):
self.map = map
self.base_paste_url = self.map.normalize_url(base_paste_url)
self.base_path = base_path
self.builder = builder
def __setitem__(self, url, app):
if isinstance(app, (str, unicode)):
app_fn = os.path.join(self.base_path, app)
app = self.builder(app_fn)
url = self.map.normalize_url(url)
# @@: This means http://foo.com/bar will potentially
# match foo.com, but /base_paste_url/bar, which is unintuitive
url = (url[0] or self.base_paste_url[0],
self.base_paste_url[1] + url[1])
self.map[url] = app
def __getattr__(self, attr):
return getattr(self.map, attr)
# This is really the only settable attribute
def not_found_application__get(self):
return self.map.not_found_application
def not_found_application__set(self, value):
self.map.not_found_application = value
not_found_application = property(not_found_application__get,
not_found_application__set)